London, April 27 (Reuters): A mutation in a gene in fruit flies may help scientists devise new therapies to ensure people get a good night?s sleep.

American scientists today said they have identified a fault in a gene that enables the insects to reduce their need for sleep by a third. They believe the findings, which are reported in the science journal Nature, could provide a new approach to treating sleep problems in humans.

?The more behaviours we look at, in terms of sleep, the more we find that sleep in fruit flies is very, very similar to sleep in mammals,? said Chiara Cirelli of the University of Wisconsin Medical School.

Fruit flies are a model organism for study because of the similarities in their genetic make-up to that of humans.

Like humans, fruit flies sleep anywhere from six to 12 hours each night. Most people need about eight hours of sleep to function properly but some can get by with just three or four.

?We wanted to determine which genes underlie this phenomenon in order to shed light on the mechanisms and functions of sleep,? said Giulio Tononi who headed the research team.

Instead of focusing on circadian rhythms, the internal body clock that controls the timing of sleep, the scientists studied factors linked to sleep duration, which is not well understood.

They screened 9,000 mutated fruit flies and found one line that required a third of normal sleep. The flies functioned normally but did not live as long as other fruit flies.

In normal fruit flies, the gene, called Shaker, produces an ion channel that controls the flow of potassium into cells. Recent studies suggest that potassium may be involved in sleep in humans.

?The research offers the possibility of developing a new class of compounds that could affect potassium channels in the brain rather than other brain system chemical systems targeted currently,? Cirelli said.